Injection Mold Core Plate Lead Screw Mechanism
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Solution Overview
Problem
Existing injection molding technologies face challenges in efficiently manipulating and ejecting molded articles with internal threads without damaging the threads, and in reducing wear on mold components during the ejection process.
Innovation Solution
A mold apparatus with a core plate and lead screw mechanism that synchronizes the rotation and translation of core plates to unscrew the core first portion from the article first portion, while a clutch allows for rotational adjustment of the core first portion without axially moving the core plate, and a manipulation mechanism using servomotors to move the engagement member to close the article second portion relative to the article first portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the core plate is axially translated to eject the molded article, then the ejection function is achieved, but the lead nut and lead screw are subjected to axial forces that increase wear and reduce component lifespan
Solution Approach 1:
The patent extracts the axial force transmission path from the lead screw mechanism by introducing a separate ejection mechanism (ejection pins or ejector plate) that handles axial ejection forces independently. This allows the lead screw to focus solely on rotational positioning without bearing axial loads, thereby reducing wear and extending component lifespan while maintaining effective ejection function.
Solution Approach 2:
The patent introduces an intermediary ejection mechanism between the core plate and the molded article, which mediates the axial force transmission. Instead of the lead screw directly transmitting axial forces during ejection, the intermediary ejection mechanism absorbs these forces, protecting the lead screw and lead nut from excessive wear while enabling successful article ejection.
2Ease of operation
If the core first portion is rotated to unscrew from the article first portion, then the threaded connection is released, but the synchronization between rotation and axial translation becomes complex
Solution Approach 1:
The patent merges the rotational unscrewing function with the axial ejection function into a single coordinated motion sequence. By synchronizing the rotation of the core first portion with the axial translation of the core plate, the system achieves both threaded connection release and article ejection through an integrated mechanism, reducing overall system complexity despite the synchronized motion requirement.
Solution Approach 2:
The patent performs preliminary rotation of the core first portion to unscrew it from the article first portion before executing the main axial ejection stroke. This preliminary action separates the threaded connection release from the force-intensive ejection phase, simplifying the synchronization requirements by preparing the threaded interface in advance before the complex coordinated motion begins.
3Device complexity
If the lead nut is fixed axially to the core plate to simplify the structure, then structural simplicity is achieved, but the lead nut cannot be isolated from axial forces during clamping
Solution Approach 1:
The patent segments the lead nut into two functional parts: one that rotates with the lead screw to provide precise positioning, and another that remains isolated from axial forces during clamping. This segmentation allows the lead nut to maintain rotational functionality while protecting it from axial wear, achieving both structural simplicity and enhanced reliability through functional separation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution ensures the efficient ejection of molded articles with intact internal threads and reduces wear on mold components by isolating the lead nut and lead screw from axial forces during clamping tonnage, thereby extending the lifespan of the mold.
Implementation Method 1
a lead screw rotatably supported by, and axially fixed relative to, the base plate; and a lead nut coupled to the lead screw and rotationally fixed relative to the core plate. The lead nut is translatable in response to rotation of the lead screw
Data Source
AI summary
A mold apparatus for producing a molded article by injection molding includes (a) a base plate for mounting to a platen of an injection molding machine; and (b) a core plate movably coupled to the base plate and axially translatable relative to the base plate between a plate advanced position and a plate retracted position. A method of resetting the core plate includes energizing a mechanical actuator in a retraction direction to exert a retraction force against the core plate and axially translate the core plate relative to a base plate from the plate advanced (molded part ejection) position to a plate retracted (mold injection) position; and then, prior to applying clamping tonnage, relieving the retraction force to axially unload the mechanical actuator, wherein the actuator is isolated from axial force exerted across the mold during application of the clamping tonnage.